Gemstone hardness chart
The Mohs scale ranks minerals 1 to 10 by scratch resistance — diamond at 10 can scratch everything else on this list; talc at 1 can be scratched by a fingernail. It's a relative ranking, not a linear one: the jump from 9 to 10 (corundum to diamond) represents a far bigger real difference in hardness than the jump from 1 to 2. Every stone tracked on this site is ranked below, hardest first.
| Stone | Mohs hardness | Variety of |
|---|---|---|
| Diamond | 10 | — |
| Ruby | 9 | corundum |
| Sapphire | 9 | corundum |
| Alexandrite | 8.5 | chrysoberyl |
| Cat's Eye | 8.5 | chrysoberyl |
| Spinel | 8 | — |
| Topaz | 8 | — |
| Aquamarine | 7.5–8 | beryl |
| Beryl | 7.5–8 | — |
| Emerald | 7.5–8 | beryl |
| Morganite | 7.5–8 | beryl |
| Black Tourmaline | 7–7.5 | tourmaline |
| Iolite | 7–7.5 | cordierite |
| Tourmaline | 7–7.5 | — |
| Amethyst | 7 | quartz |
| Citrine | 7 | quartz |
| Garnet | 6.5–7.5 | — |
| Rock Crystal | 7 | quartz |
| Smoky Quartz | 7 | quartz |
| Tiger's Eye | 7 | quartz |
| Agate | 6.5–7 | chalcedony |
| Bloodstone | 6.5–7 | chalcedony |
| Carnelian | 6.5–7 | chalcedony |
| Chrysolite | 6.5–7 | peridot |
| Chrysoprase | 6.5–7 | chalcedony |
| Hyacinth | 6–7.5 | zircon |
| Jasper | 6.5–7 | chalcedony |
| Kunzite | 6.5–7 | spodumene |
| Onyx | 6.5–7 | chalcedony |
| Peridot | 6.5–7 | olivine |
| Sardonyx | 6.5–7 | chalcedony |
| Zircon | 6–7.5 | — |
| Jade | 6–7 | — |
| Tanzanite | 6–7 | zoisite |
| Labradorite | 6–6.5 | plagioclase feldspar |
| Moonstone | 6–6.5 | orthoclase feldspar |
| Sunstone | 6–6.5 | plagioclase feldspar |
| Opal | 5.5–6.5 | — |
| Hematite | 5–6.5 | — |
| Lapis Lazuli | 5–6 | — |
| Turquoise | 5–6 | — |
| Obsidian | 5–5.5 | — |
| Larimar | 4.5–5 | pectolite |
| Malachite | 3.5–4 | — |
| Coral | 3–4 | — |
| Pearl | 2.5–4.5 | — |
| Jet | 2.5–4 | — |
| Amber | 2–2.5 | — |
What the number actually tells you
Mohs hardness is a scratch-resistance ranking, not a general durability score. A higher number means a stone is harder to scratch — full stop. It says nothing about toughness (resistance to chipping or cracking from an impact) or stability (resistance to heat, light, or chemical exposure). Opal, for instance, is a moderate Mohs 5.5–6.5 but can crack from rapid temperature or humidity changes for reasons the hardness number doesn't capture at all.
As a rule of thumb: household dust contains fine quartz particles at Mohs 7, so any stone below 7 — turquoise, opal, pearl, malachite, larimar — will slowly accumulate fine surface scratches from ordinary daily wear, which is why those stones are more often set in earrings and pendants than everyday rings. Anything at 8 and above resists that kind of wear almost entirely.
Frequently asked questions
- What does the Mohs scale actually measure?
- Scratch resistance, not toughness or overall durability. It's a relative 1–10 ranking of which minerals can scratch which others — a material higher on the scale will scratch one lower, not the reverse. A stone can be hard (scratch-resistant) but still brittle and prone to chipping or cracking from a sharp impact, which is a separate property the Mohs number doesn't capture.
- Is a Mohs 7 stone safe for everyday jewelry?
- Generally yes for rings and bracelets, which take the most abrasion — Mohs 7 is the hardness of ordinary quartz dust present in household dirt, so anything below 7 will slowly pick up fine scratches from everyday contact. Anything at 8 or above (topaz, spinel, corundum, diamond) resists that kind of wear essentially completely.
- Why do some stones on this site have no Mohs value listed?
- Group minerals like garnet and tourmaline vary enough by exact chemistry that a single number would misrepresent them, so those are given as ranges rather than nulled out. Where a value is genuinely missing here, it's because we weren't confident enough in a specific figure to state it — an honest gap rather than a guess.
Sources
Retrieved August 13, 2026.